From 06ca9d683920da19ad53532f8cd55b54584027bc Mon Sep 17 00:00:00 2001 From: antirez Date: Mon, 27 Nov 2017 19:04:58 +0100 Subject: LFU: Fix LFUDecrAndReturn() to just decrement. Splitting the popularity in half actually just needs decrementing the counter because the counter is logarithmic. --- src/evict.c | 16 +++------------- 1 file changed, 3 insertions(+), 13 deletions(-) (limited to 'src/evict.c') diff --git a/src/evict.c b/src/evict.c index 55b132123..bf485ddc5 100644 --- a/src/evict.c +++ b/src/evict.c @@ -335,19 +335,9 @@ uint8_t LFULogIncr(uint8_t counter) { unsigned long LFUDecrAndReturn(robj *o) { unsigned long ldt = o->lru >> 8; unsigned long counter = o->lru & 255; - long halve_times = server.lfu_decay_time ? LFUTimeElapsed(ldt) / server.lfu_decay_time : 0; - if (halve_times > 0 && counter) { - if (halve_times == 1) { - if (counter > LFU_INIT_VAL*2) { - counter /= 2; - if (counter < LFU_INIT_VAL*2) counter = LFU_INIT_VAL*2; - } else { - counter--; - } - } else { - counter = counter >> halve_times; - } - } + unsigned long num_periods = server.lfu_decay_time ? LFUTimeElapsed(ldt) / server.lfu_decay_time : 0; + if (num_periods) + counter = (num_periods > counter) ? 0 : counter - num_periods; return counter; } -- cgit v1.2.1